This invention relates to an apparatus for providing accurate point location information particularly in relation to X and Y coordinates on a surface such as a drafting board, for example, through the use of a unique electro-mechanical system which supplies analog information to an analog-to-digital converter and onward to a suitable recording system. The resulting information is utilized in a highly effective and efficient manner, particularly for the purpose of affixing data to the surface of a drawing or the like.
In current practice it is common to use graphic digitizers to convert graphic information into computer-acceptable form. Systems for accomplishing such results permit the operator to locate a series of selected points or lines upon a surface. Such apparatus is used widely, in conjunction with engineering drafting procedures, for cartography activities.
It has been found in utilizing systems of this character for engineering drafting purposes that while they are effective in reducing the time required for the preparation of the drawings themselves, little attention has been given to the use of time-saving apparatus for accurately locating the best positions and entering upon the surface of such drawings appropriate information in the nature of technical notes, legends, symbols, identifying indicia, etc. Through the utilization of the present invention, the draftsman, cartographer and people in many technical regimes can save valuable time in printing such messages upon the surfaces of drawings or the like through the expedients provided by the point locator and digitizer of this invention. They may thereby define at various locations upon the face of the document of interest the beginning positions for the messages to be affixed thereupon. That information to be affixed to the surface may then be entered directly, the total location and message information being supplied to a digitizer and recorded in a suitable form such as, for example, a magnetic memory, a magnetic tape or the like.
The preferred embodiment of this invention is in the form of a single housing unit which encompasses a pair of potentiometers. The potentiometers are actuated by an extensible arm, an extremity of which has a cursor attached thereof. The potentiometers are electrically connected through an A/D converter to a digitizer and a recording device. However, the specific structural form of the invention may vary to include a pair of separately housed potentiometers independently connected to extensible and/or rotatable arms, the only requisite being the use of a single cursor which, when moved, is capable of indicating the dual X and Y axes inputs required for point locations.
An objective of this invention is to provide in a locator system an implementing combination of elements for accurately locating upon the surface of a document the desired positions for the introduction of printed or graphic information to be applied to that document, transferring, storing and retrieving the location data and utilzing that data in accomplishing the printing or graphic function.
Another objective is to provide in a digitizer system those components required for generating and recording digital information responsive to analog signals and representative of a plurality of point locations upon a flat surface, such information being retrievable for use in systematically applying pre-recorded data to that surface in relation to the point locations.
It is another objective of the invention to provide an improved means for generating as a pair of voltages an signals representative of a given point upon a surface.
A further objective of the invention is to provide an improved data input device for a high-speed electronic data processor which provides electrical signals representative of radial and angular displacements of a pre-determined point upon a surface.
Yet another objective of the invention is to provide an improved means for generating electrical data, including a movable cursor, the position upon a surface of which results in the regeneration of a pair of electrical signals representing the X and Y coordinates of the position of that cursor.
Yet another object of the invention is to provide an improved system for locating a series of given points upon a surface and generating voltages representative of the coordinates of those points and supplying those voltages to a converter for transforming analog signals into digital form.
Still another objective of this invention is to provide means whereby analog signals supplied to an analog-to-digital converter, digitized, and recorded may be retrieved and utilized to drive a printer over a surface from which the data was originally derived and printing pre-determined data upon that surface at pre-determined locations.